Hi Hamad

Bounded et al (Oncogene Vol. 18 Issue 31, p4440) studied why invasive breast cancer cells have the ability to extend membrane protrusions, invadopodia, into the extracellular matrix (ECM). These structures are associated with sites of active matrix degradation. The amount of matrix degradation associated with the activity of these membrane protrusions has been shown to directly correlate with invasive potential. They demonstrated  that microinjection of polyclonal anti-cortactin antibodies blocks matrix degradation at invadopodia supporting the hypothesis that cortactin has a direct role in invasive behavior. MDA-MB-231, invasive breast cancer cells were sheared from the surface of a gelatin matrix to isolate invadopodia. Cortactin, paxillin and protein kinase C (PKC) μ, a serine kinase, were co-immunoprecipitated as a complex from invadopodia-enriched membranes. They confirmed the subcellular distribution of these proteins by immunolocalization and Western blotting. We also determined that, in contrast to its presence in invasive cells, this complex of proteins was not detected in lysates from non-invasive cells that do not form invadopodia. Taken together, these data suggest that the formation of this cortactin-containing complex correlates with cellular invasiveness. They hypothesize that this complex of molecules has a role in the formation and function of invadopodia during cellular invasion.

Hope is useful. Best regards.

Daniel

Many thanks, Dr. Daniel